Wireless communications systems allow a subscriber telephone communications even though the subscriber may be traversing the wireless communications system of the subscriber's service provider or roaming outside the service provider's wireless communication system. However, communications to the subscriber may not be possible if radio frequency (RF) coverage is not ubiquitous or if a service agreement between the subscriber's service provider and the operator of another wireless communications system is not established. Moreover, there are situations, such as when in a court of law, when the subscriber does not wish to be disturbed. In such cases, the subscriber may wish to have the call sender deposit a voice message so that the subscriber can retrieve the voice message at a later time.
With the prior art, the subscriber may write the call sender's directory number (DN), disconnect from the voice messaging system, and dial the call sender's DN. Once the subscriber has completed the call with the call sender, the subscriber may wish to return to the voice messaging system. In such a case, the subscriber reconnects with the voice messaging system and navigates to the next voice message. This process is very cumbersome and user-unfriendly.
As an alternative to the manual process described heretofore, a voice messaging system (VMS) may use a front-end switch and a telephone facility configuration that enables the subscriber to navigate between the voice messaging system and the call sender. FIG. 1 illustrates an architecture of wireless communications system 100 that provides voice messaging service according to the prior art. The subscriber, through wireless device 101, accesses the subscriber's voice mailbox located on voice messaging system (VMS) 104 through radio link 110, serving mobile switching center (MSC) 102, interface 111, home MSC 103, and interface 112. With the architecture shown in FIG. 1, the subscriber may be listening to a voice message that has been deposited by a call sender 106. VMS 104 has previously collected the directory number (DN) of call sender 106 when call sender 106 deposited the voice message. The collection of the call sender's DN can be obtained through means such as collecting the corresponding digits through a corresponding signaling system 7 (SS7) message that contains the call sender's DN. Alternately, the digits can be collected by prompting call sender 106 in conjunction with a touchtone keypad or through automatic speech recognition. In order for the subscriber to reply to call sender 106 in response to the voice message, the subscriber can enter a feature code (e.g. *88). VMS 104 recognizes the subscriber's request and establishes a call to call sender 106 through facility 113, facility 114, network 105, and facility 115 to call sender 106.
In the architecture shown in FIG. 1, VMS 104 configures the call through an additional facility 113 in order to complete the call. The architecture in FIG. 1 utilizes a front-end switch that is integrated with VMS 104, although an alternate architecture can utilize a separate front-end switch according to the prior art. Because facilities 111, 112, and 113 use resources on serving MSC 102 and home MSC 103, and interface ports on VMS 104 are utilized during the entire time duration of the call, the cost for the service provider to offer the voice messaging service can be substantially increased. The facility configuration associated with the call enables VMS 104 to monitor the call throughout the time duration of the call. Because VMS 104 (in conjunction with facility 113) “camps-on” the call, the subscriber may request to return to the voice mailbox after completing the call to the call sender.
These examples underscore the need for providing a solution that enables the subscriber to navigate between the subscriber's voice mailbox and a call to a call sender and that obviates the need for additional facilities that must be configured during the time duration of a call. Such a solution will provide the customer with an efficient means for returning calls to voice messages while reducing the associated costs to the wireless service provider.